[js1138]

To most people, the phrase "common ancestor" means a single living cell from which all subsequent life sprang.

Most people know little or nothing about biology.

The first cell may or may not have been a unique event. The first three billion years of life are erased.

[metmom]

Most people know little or nothing about biology.

What do you know about science or biology? What field is your degree in?

[Alamo-Girl]

Most people know little or nothing about biology.

This is a case-in-point to my previous post.

Biology is the study of life. And yet if you ask "what is life v. non-life/death in nature?" the answers from biologists will be mostly descriptive, e.g. properties of living organisms.

The ones focused on what life and non-life/death "is" not just what it looks like will be mostly theologians, philosophers, mathematicians and physicists.